hamas fighters have fired hundreds of rockets into israel including 75 today. one hit an empty school. at least three israelis have been killed since the attacks began last week. reporter sara sidner is in gaza where the attacks are becoming more deadly by the day. >> people are picking out things, anything they can find and if you look to your right, destruction, the building next to it blown out. and we are standing on what was the roof of a three-story building. >> reporter: israel has not ruled out a ground invasion of gaza, prime minister benjamin netanyahu says the israeli military is prepared to escalate its operations if necessary. >>> president obama is overseas in cambodia this hour. coming up in about eight minute, the importance of a visit from the first sitting president to that country. >>> a two-alarm fire at a russian river resort sent four people to the hospital and knocked out power lines early this morning. the fire started around 3:45 at the guerneville lodge on river road. it took about 45 minutes to get it under control. the red cross was